Hey there Grunchvark,
It sounds like your Safari is not loading the content of your webmail service correctly. I have a couple of things for you try. First check for 3rd party plug ins that may be interfering with the messages loading:
Safari: Unsupported third-party add-ons may cause Safari to unexpectedly quit or have performance issues
If there are none, or the issue persists then I would next reset Safari and try the page again.
Safari 6 (OS X Mountain Lion): Reset Safari
Safari 5.1 (OS X Lion): Reset Safari
Depending on the version of Safari you have.
Thank you for using Apple Support Communities.